Rope modelling issue - curve modifier breaks up if object moved from origin
If you move the object away from the curve, on some axis, it may mess up the array, so put the origin of the curve at its beginning point, put the object at the same position, give it the Array and the Curve modifiers, and if you want your object to be somewhere else, select BOTH the object and the curve. As Metaphor said, to make it easier you can parent the curve to the object.